Hull coach Peter Gentle is stepping up preparations for the biggest match of his career as he bids to take the struggling Black and Whites to Wembley.

Gentle has taken his players to an agricultural college in picturesque east Yorkshire to prepare for Sunday's Tetley's Challenge Cup semi-final against holders Warrington at Huddersfield.

Gentle accepts his side will go into the tie as rank underdogs after losing their last five Super League matches and he has a host of injury concerns but he insists his players have not lost their self-belief.

"It's the biggest game I've coached or been involved in. To be this close, you can almost touch it, but we need a very good performance," Gentle told a news conference at Bishop Burton.

"It's a massive week. We're that excited about it, the players, the fans, the staff - everyone involved with the club.

"It's been on our radar for quite a few weeks. It may have been a distraction, I'm not sure, but it's here now.

"We've changed things as we do for the Cup weeks. We're spending a fair bit of time up here at Bishop Burton this week. The boys love it here and the facilities are first class.

"It's just a break from normality. The importance of this game is not lost on anyone."

Gentle, whose side's last Wembley appearance was in 2008, has already ruled out leading tryscorer Ben Crooks and has injury doubts over forward Liam Watts and half-backs Richard Horne and Daniel Holdsworth, who were all wearing surgical boots at training on Monday to combat the effects of ankle injuries.

Former Castleford centre Joe Arundel will take the place of Crooks, who has scored 19 tries so far in his first full season of Super League but may not play again this year after picking up a worrying ankle injury in the 19-12 defeat at Bradford last Friday.

"There's not a break," Gentle said.

"We've had the x-rays done and now we're waiting for the MRI scans to come back.

"I'm not sure how long he will be out but it's not short term.

"It's a big blow for us. He's been in form."

England winger Tom Briscoe was another to sit out training on Monday and Gentle says he is likely to leave his team selection until as late as the day of the game

"We've got a lot of doubts," he said. "We've had to get a couple of extra boots in.

"We'll give them right up to the captain's run. Hopefully we'll get a few surprises later in the week.

"It's not ideal but I'm comfortable that, with whatever 17 we put out there, we will give our fans something to shout about."